Extracting copper from its ore

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Introduction

Extracting copper from its ore "Low-grade" ore is carefully poured on specially treated impermeable ground for ease, all in affect to later drain away the copper ion solution. Afterwards, the bacteria can then be sprayed, requiring acidic conditions involving a supply of Fe2+/S2- ions, carbon dioxide, oxygen, nitrogen and phosphorous containing nutrients. Furthermore, thiobacillius ferro-oxidans and thiobacillius thio-oxidans obtain the energy to survive/live by oxidising Fe2+/S2- ions; as a result they release the required metal ions into solution.[1] The copper ion solution can then be drained, allowing the copper ions to be removed using the aid of another solvent in a ligand exchange reaction. The term "ligand" refers to a specific compound with a lone pair of electrons that binds with the metal compounds to form a complex.[2] The ligand can be dissolved in an organic solvent such as kerosene, which is immiscible in water: Cu2+ (aq) + 2LH (organic) CuL2 (organic) + 2H+ (aq) Note: the "L" represents the ligand. ...read more.

Middle

E.g. arsenopyrites. The minerals are oxidised and made water soluble, leaving behind the insoluble gold particles. The oxidation reaction is carried out by sulpholobus acidocalderius in the presence of oxygen and water at a low pH. Firstly, sulpholobus acidocalderius catalyses the formation of iron, arsenic and sulphur compounds: FeAsS Fe (II) + As (III) + S (VI) Note: the arsenic and sulphur have been oxidised in this reaction. Further oxidation of Fe (II) and As (III) then occurs: Fe (II) Fe (III) As (III) As (V) Note: all products are water-soluble: 2FeAsS + 7O2 + 4H+ + 2H2O 2Fe3+ + 2H3AsO4 + 2HSO4- Lastly, the gold remains solid after the separation from liquid and the pH is raised with the aid of lime; using the method of cyanidation, the gold can be extracted.[3] Advantages and disadvantages of bacterial leaching Bacterial leaching is environmentally friendly; bacterial-leaching solutions can be recycled. The water pollution problems that may result from acid mine drainage are difficult to clean up. ...read more.

Conclusion

Referring back to the initial location of the ore, the site of the plant must be in within a reasonable range to a specific market. If however, the plant were not near to a market, the cost of transporting the goods would be very expensive; again less profit would be made. Lastly, the effect of setting up a plant will increase employment and may attract people to the site. However, this can also have its disadvantages; if the plant were to be set up near a quiet country-side village, conflict will be made as some of the local residents may complain of noise discomfort, pollution etc... Summary of development stages that a new mining process must pass before commercially operating A chemist must first discover and invent a new process in the lab. After which, a test scheme can be set up to see how successful the idea actually is. Then, the cost of the operation must be taken into account; only then will the procedure commence once all the targets are met. ...read more.

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